The Lime Kilns wrap around the waterfall that the suburb of Menomonee Falls was named after. About 20 mins. outside of Milwaukee, Menomonee Falls was a small village, with the waterfall and park at its center. The waterfall is at the end of a pond, with a bridged street over it's river. The river leads all through the park, which has small bridges, paths and old stone Lime Kilns. There are open hidden spaces in the middle of the wooded areas, with lots of tree stumps that can be used as seats, and can keep others from seeing you. Since there are so many tree branches and trees, you'd be able to hear someone coming in advance.
Check out this page, it has moving pictures hah http://www.menomonee-falls.org/index.aspx?nid=149